Figured it out!
Give the Querydef a name as follows:
strSql = Me.lstUsage.RowSource
Set qdfTemp = CurrentDb.CreateQueryDef("qryTemp", strSql)
filePath = "D:\Documents\Access\Mine\Finances\ExportedData.xlsx"
DoCmd.OutputTo acOutputQuery, "qryTemp", acFormatXLSX, filePath, True...